It can be quite easy to pick up an ear infection in a shared pool, especially if you are in a hot country as bugs proliferate more quickly in the heat.

The most common form is otitis externa, which means infection of the skin of the ear canal. There are simple ways of protecting her ears, such as earplugs or a headband designed for swimming, which covers the ears. You should be able to find these at a high street or airport chemist.

Alternatively, make your own earplugs. Take two small pieces of cotton wool, each about the size of a large grape, and dab them in a jar of Vaseline. Knead the cotton wool until the Vaseline is thoroughly mixed in, then place each in the outer cupped part of her ear. You don’t need to push them in. She may need to wear a swimming cap to keep them in place. After swimming, let her ears dry naturally. If there’s water in them, encourage her to turn her head to one side, then the other, until it drains out. Don’t be tempted to get the water out by putting the end of a towel into her ear or using a cotton bud. This could traumatise the delicate skin in the ear canal and a break in the skin can be the entry route for infection.

When her ears are dry you could use ear spray or drops that are designed to sterilise the ears after swimming to minimise the chance of infection. You should be able to find them at an airport chemist. Ask the pharmacist’s advice on the most suitable brand for your daughter).

If she does succumb to another ear infection, it’s best to get it treated quickly. Anti-biotic ear drops are the most effective form of medication.

Chickenpox fear

My four-year-old daughter had a friend round for tea two weeks ago who the following day developed spots and had chickenpox diagnosed. My daughter has not had chickenpox and I expected her to develop it too, but she hasn’t. Is it possible that she is already immune? Name and address supplied

The incubation period for the virus that causes chicken- pox can be up to 21 days, so if your daughter came into contact with it for the first time two weeks ago she could still develop symptoms. Chickenpox is very contagious and the transmission rate is almost 100 per cent. She may have have experienced an extremely mild form of chickenpox since playing with her friend that was virtually unnoticeable. I think you’ll have to wait another week or so to find out.

Jane Collins is the chief executive and honorary consultant paediatrician at Great Ormond Street Hospital